Table of Contents
Advertisement
DIDS-402-2AM13
These steps should be performed each time power is initially applied to
the Display Terminal to prevent damage to the monoscope.
After 3 minutes, advance the on/off brightness control further clockwise
until horizontal scan lines approximately 0.13 inch high are visible on the CRT
screen.
2-3.3.2 Delay-Line Adjustment
The following conditions indicate the necessity for a delay-line adjustment:
character shifting, moving characters, flashing presentation, multiple cursors,
or cursor disappearance when CURSR RESET is released.
Note
Do not attempt delay-line adjustments until it
is absolutely established that the Display Ter-
minal has had adequate time (3 to 5 minute s)
to warm up and that an adjustment is necessary.
If the need for adjustment is established. it should
not be necessary to adjust either delay line more
than six turns in either direction from the factory
adjustment.
The delay line is adjusted by performing the following procedure:
a.
Refer to figure 1-3.
Remove the wire from terminal 7 of Display
Logic Board Al3.
b.
Using a dual-input oscilloscope (Te.ktronix Type 545A with Type CA
plug-in unit or equivalent). refer to figure 1-5 and connect the
oscilloscope as follows:
(1)
External trigger to delay-line electronics
A9.
terminal E.
Switch oscilloscope to minus ( - ) extension trigger.
(2)
Connect one input probe to delay-line electronics
A9.
terminal E. and the second to A6, pin 4.
c.
On the top delay line (see figure 2-2), turn the adjustment screw until
the falling edges of the clock pulses are aligned with the centers of the
peaks of the sine waves (see figure 2-3).
(The waveforms shown are
not repre s entative of any particular character. )
d.
Reconnect the wire to terminal 7 of Display Logic Board A13.
e.
Alternately depress and release the CURSR RESET key and
simultaneously adjust the bottom delay line adjustment screw
(see figure 2-2) until the screen displays stable characters and the
cursor remains visible when the CURSR RESET key is released.
2-5
Advertisement
Chapters
Table of Contents
